The proposed project addresses the issues of motor function and quality of life in patients with stroke as described in NIH PA-02-111. Many patients who have sustained strokes are unable to effectively use their hemiparetic upper extremity. Limited mobility in the performance of daily activities, such as eating or dressing, adversely affects their quality of life and compromises independence. Rehabilitation techniques engaging the hemiparetic limb in repetitive task practice (RTP) may improve upper extremity function and quality of life in patients with stroke, but costs limit the number of patients that can utilize this type of therapy. Advances in microprocessor design and function make the use of an assistive device as an adjunct to RTP plausible. An innovative assistive repetitive motion (ARM) device using an "air muscle" has been developed specifically for the rehabilitation of the hemiparetic upper extremity. The primary aim of the proposed study is to collect pilot data to estimate the clinical effectiveness of using the ARM device in conjunction with RTP to improve upper extremity motor function and the quality of life of patients with stroke. Twenty sub-acute (3 to 9 mos. post-stoke) patients will be randomized to one of three groups: ARM only, RTP only or RTP + ARM group. The ARM group will use the ARM for four hours per day for 15 days. The RTP group will receive 15 days (4 hours per day) of intensive one-on-one RTP therapy. The ARM + RTP group will use the ARM device for 2 hours per day and receive 2 hours of intensive RTP per day for 15 days. Clinical motor function and quality of life measures will be taken before and after the interventions and two months later. We hypothesize that the ARM + RTP group will exhibit greater improvements in motor function and quality of life measures than the ARM or RTP only groups. Gathering quantitative motor (kinematic and kinetic) and imaging (fMRI) data from a subset of patients in each group to examine potential mechanisms contributing to improved motor function constitute unique addenda to this study. The results from this project will provide valuable data as a pre-requisite for submission of a multi-year R01 randomized clinical trial to determine the efficacy of using an assistive device, such as the ARM, as an adjunct to RTP. This project has the potential to increase the availability of effective rehabilitation techniques to patients with stroke.